Process for protecting a substrate with an n{hu 4{l -pyridylaminoarylsulfonamide intumescent agent

ABSTRACT

Intumescent compositions of the invention comprise certain N4pyridylaminoarylsulfonamides, such as the N4-2-, 3-, and 4pyridylsulfanilamides. The intumescent agents may be employed in conjunction with additives conventionally used in intumescent compositions. For use in protecting substrates from heat and fire, the intumescent compositions may be applied in any suitable manner, such as by electrodeposition, spraying onto an adhesive substrate, or application of a coating composition comprising the intumescent agent.

United States 1 3,775,167

Roth 11 Nov. 27,1973

[ PROCESS FOR PROTECTING A Chem Abs., Vol. 33, No. 7796-2 (1939) SUBSTRATE WITH AN Chem Abs., Vol. 35, No. 3986-8 (1941) N4-PYRIDYLAMINOARYLSULFONAMIDE' Chm m, v01, 56, No.'8682a (1962) INTUMESCENT AGENT 1 [75] Inventor: Shirley H. Roth, Highland Park, NJ. primary E i wi11i D M i Assistant Examiner- Harry J. Gwinnell [73] Assigneez Cities Service Company, New York, Attorney Richard S. strickler et a1 [22] Filed: Feb. 28, 1972 57 ABSTRACT [21] Appl. No.: 230,134

Intumescent compositions of the invention comprise certain N -pyridylaminoarylsulfonamides, such as the [52] [1.5. Cl. 117/136, 106/15 FP N -2-, 3-, and 4-pyridylsulfanilamides. The intumes-' [51] Int. Cl. C09d 5/18, C09k 3/28 cent agents may be employed in conjunction with ad- [58] Field of Search 117/136, 239.8; ditives conventionally used in intumescent composi- 106/ 15 FP; 252/8.l tions. For use in protecting substrates from heat and fire, the intumescent compositions may be applied in [56] References Cited any suitable manner, such as by electrodeposition, UNITED STATES PATENTS spraying onto an adhesive substrate, or application of 2 426 313 8/1947 Ludwig at al 260123995 x a mating mposition comprising the intumescent 3,535.130 10/1970 Webb 117/136 X agent- 3,663,464 5/1972 Sawko 117/136 X 3,707,554 12/1972 l-lardy 117/136 x OTHER PUBLICATIONS Chem Abs., Vol. 33, No. 5377-9 (1939) 6 Claims, No Drawings PROCESS FOR PROTECTING A SUBSTRATE WITH AN N4-PYRIDYLAMINOARYLSULFONAMIDE INTUMESCENT AGENT l BACKGROUND OF THE INVENTION 1. Field of the Invention v This invention relates to intumescent compositions and more particularly relates to such compositions containing a one-component intumescent agent.

2. Description of the Prior Art It is known that a substrate may be protected from heat and fire by the application of an intumescent composition. lntumescent compositions of the prior art usually contain an intumescent agent having at least three components; i.e., a carbonific, a spumific, and a catalyst; and they are typically characterized by the disadvantages of high cost, low spreading rate, relatively poor efficiency, poor water resistance, and poor weatherability.

As disclosed in U. S. Pat. No. 3,535,130, it has already been discovered that a one-component intumes cent agent has advantages over multicomponent intumescent agents. However, the intumescent agents of the patent have poor adherence to substrates and have an undesirable degree of moisture sensitivity.

SUMMARY OF'THE INVENTION An object of this invention is to provide a novel class of one-component intumescent agents.

Another object is to provide such intumescent agents having good efficie'ncy and a low level of moisture sensitivity.

These and other objects areattained by using as intumescent agents compounds corresponding to the formula:

wherein Aris a divalentaromatic residue, R is a pyridyl or substituted pyridyl radical, and R is are hydrogen, hydrocarbon, substituted hydrocarbon, or acyl.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The intumescent agents of the invention may be any compounds corresponding to the above formula. However, they are preferably compounds wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy,

halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof. When the aromatic ring bears organic substituents, it is usually preferred that these substituents contain one-five carbon atoms. When there are halo substituents, it is usually preferred that they be chloro or bromo. It is also preferred that the aromatic ring have at least one free reactive position.

R of the above formula is preferably a pyridyl radical, but it may bear one or more substituents if desired. The substituted pyridyl radicals most commonly found in these compounds are the chloro, bromo, carboxy, hydroxy, amino, amido, nitro, sulfonamido, sulfo, C C alkyl, C C alkoxy, phenyl, and benzo derivatives, but compounds containing other substituted pyridyl radiare N2-pyridylsulfanilamide, N-3-pyridylsulfanilamide, N"-4-pyridylsulfanilamide, 4-( 2- pyridyl)-amino-3-chlorobenzenesulfonamide, 2-( 2- pyridyl )amino-4-bromobenzenesulfonamide 4-( 2- pyridyl)amino-2-ethylbenzenesulfonamide, 3-( 2- pyridyl )amino-4-chloromethylbenzene-sulfonamide, 4-( 2-pyridyl )aminc-2-butoxybenzenesulfonamide, (2-pyridyl )amino-3-chloromethoxybenzenesulfonamide, 4-( Z-pyridyl )amino-3-hydroxybenzenesulfonamide, 4-( '2-pyridyl )am ino-3-carboxybenzenesulfonamide, 4-( 2-pyridyl )amino-3- aminobenzenesulfonamide, 4-(2-pyridyl)-ami no-2- acetamidobenZenesulfonamide, 2-(2-pyridyl)amino-4- nitrobenzenesulfonamide, N-( 6-chloro.-3- pyridyl)sulfanilamide, N -(5-bromo-2- pyridyl )sulfanilamide, N 3carboxy-2- quinolyl)sulfanilamide, N-(6-hydroxy-2-pyridyl)- sulfanilamide, N-(S-amino-Z-pyridyl)sulfanilamide, N- 2-amido-3-pyridyl )sulfanilamide, N-( 5-nitro-2- pyridyl)-sulfanilamide, N -(5-sulfonamido-2- pyridyl)sulfanilamide, N -(5-sulfo-2- pyridyl)sulfanilamide, N"-( 2-methyl-4- quinolyl )sulfanilamide, N-( 6-ethoxy-2-methyl-4- quinolyl )sulfanilamide N( 2-phenyl-4- quinolyl)sulfanilamide, N -2-quinolylsulfanilamide, N- ethyl-N-2-pyridylsulfanilamide, N-(4.-aminophenyl)- N -2-pyridylsulfanilamide, N'-(4-sulfonamidophenyl)- NTZ-pyridyIsuIfaniIamide, N -(4-nitrophenyl )-N"-2- pyrid-ylsulfanilamide, N-acetyl-N-2- pyridylsulfanilamide, the corresponding naphthalene compounds, etc.- When not readily available, these compounds may be prepared by known techniques.

For use in protecting a substrate from heat and fire, the intumescent agents of the invention may be applied in any suitable manner, e.g., electrodeposition, spraying of powdered intumescent agent onto an adhesive substrate, etc, However, it is usually preferred to compound the intumescent agent with a binder, e.g., nitrocellulose, and optionally also with one or more of the other ingredients conventionally used in intumescent compositions, e.g., stabilizers, dispersing agents, pigments, driers, biocides, anti-foamers, thickeners, protective colloids, fillers, blowing agents, etc.; disperse the composition in a suitable liquid medium, e.g., water or a solvent or solvent mixture; and apply the coating composition thus formed to the substrate to be protected. As is the case with conventional intumescent coating compositions, it is frequently convenient to apply these coating compositions in the form of a paint having a solids content of about 10-70% by weight and an intumescent agent/binder weight ratio of about 0.075-14/1 to deposit a coating having a dry thickness of about 0.00l-0.75 inch.

The intumescent agents of the invention are efficient, have low moisture sensitivity, and intumesce to form foams having good volume, cell structure, and adher-' They are also useful as flame retardants in normally flammable compositions.

The following example is given to illustrate the invention and is not intended as a limitation thereof.

EXAMPLE I Place one gram of N -2-pyridylsulfanilamide in an aluminum pan and flame it with a propane torch. The compound intumesces to form an excellent volume of foam having a good cell structure.

Similar results are also observed when N -2- quinolylsulfanilamide and the other intumescent agents mentioned in the specification'are substituted for the intumescent agent of the Example.

It is obvious that many variations may be made in the products and processes set forth above without departing from the spirit and scope of this invention.

What is claimed is:

1. A process for protecting a substrate from heat and fire which comprises applying thereto an intumescent composition comprising as the intumescent agent a compound corresponding tothe formula:

wherein Ar is a divalent aromatic residue, R is a pyridyl or substituted pyridyl radical, and R is hydrogen, hydrocarbon, substituted hydrocarbon, or acyl.

2. The process of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.

3. The process of claim 1 wherein R is a pyridyl radi cal or a carboxy, amino, nitro, alkyl, alkoxy, phenyl, or benzo derivative thereof.

4. The process of claim 1 wherein R'is hydrogen, al kyl, phenyl, aminophenyl, sulfoamidophenyl, nitrophenyl, or acetyl.

5. The process of claim 1 wherein the intumescent agent is N-2-pyridylsulfanilamide.

6. The process of claim 1 wherein the intumescent agent is N -2-quinolylsulfanilamide. 

2. The process of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.
 3. The process of claim 1 wherein R is a pyridyl radical or a carboxy, amino, nitro, alkyl, alkoxy, phenyl, or benzo derivative thereof.
 4. The process of claim 1 wherein R'' is hydrogen, alkyl, phenyl, aminophenyl, sulfoamidophenyl, nitrophenyl, or acetyl.
 5. The process of claim 1 wherein the intumescent agent is N4-2-pyridylsulfanilamide.
 6. The process of claim 1 wherein the intumescent agent is N4-2-quinolylsulfanilamide. 